1. Field of the Invention
The present invention relates to a leadthrough for passing conduits through a constructional component and including a circumferentially closed housing that surrounds a pass-through space for a conduit, an insert of intumescent material located in the housing, and a first, diaphragm-shaped sealing member formed of an elastic material, having a through-opening, and likewise located in the housing.
2. Description of the Prior Art
Leadthroughs of the type discussed above are used for passing conduits such as, e.g., tubular conduits, cables or cable channels through constructional components such as, e.g., ceilings or walls.
The leadthroughs are embedded in the constructional components during their manufacturing. In particular, the leadthroughs can be cast in the concrete ceilings and walls. The leadthroughs are provided with an insert of an intumescent material, with the insert performing a fire-protection function. Thereby, a fire-protection is already available from the time of embedding or casting of a leadthrough in a constructional component, through installation of a conduit through the leadthrough, and up to finishing of a building.
In case of fire, in addition to flames having high temperatures, also flue gases are produced. The flue gases can penetrate, before the intumescent material is activated, into adjacent space through an annular slot between the conduit, which extends through the leadthrough, and the inner wall of the leadthrough housing.
European Publication EP 1 495 248 A1 discloses a leadthrough for passing conduits through a constructional component and having a circumferentially closed housing that surrounds a pass-through space for a conduit, an insert of intumescent material located in the housing, and a sealing member formed of an elastic material. The sealing member engages the conduit, which extends through the leadthrough, and seals the annular slot between the conduit and the inner wall of the housing against flue gases.
The drawback of the solution, which is proposed in the prior art, consists in that the hot flue gases, i.e., flue gases with high temperatures, which are generated during fire, melt the seal, which is provided by an elastomeric material, away before the intumescent mass is activated and closes the pass-through space of the housing. The hot flue gases can flow then through the annular slot, whereby burning-off of the side of the conduit adjacent to the constructional component and which was not expose to fire, is accelerated. If the conduit is melted away and the intumescent material has not yet completely expanded, the flue gases and flame, as the case may be, can reach unhindered the other side of the constructional component.
Accordingly, an object of the present invention is a leadthrough with which penetration of both cold and hot flue gases through the annular clearance between the conduit and the inner wall of the housing before activation of the intumescent material is reduced to a most possible extent.